This invention relates to a device for chopping food, particularly ice cubes, according to the prior-art portion of patent claim 1.
The prior art knows of a multiplicity of devices for chopping food. For example, EP-A-0 211 392 and U.S. Pat. No. 5,360,170 describe an attachment for an electric kitchen appliance having a freely rotatable chopping tool mounted on the bottom of a cylindrical container. Food such as fruit, vegetables, ice cubes or the like is chopped by a part of the food being severed by the blades of the chopping tool with each rotation. The fact that the chopping tool is positioned in close proximity to the bottom means that the food which comes to rest in the lower part of the container is chopped more often than the food which comes to rest in the upper part of the container unless the food is optimally mixed.
EP-A-0 174 407 describes a device of the type initially referred to, in particular for chopping ice cubes, having an upper container equipped with a processing zone for chopping the food and an adjoining collecting zone for receiving the food. The unprocessed ice cubes are held in a rotary cylinder of the processing zone, which is enclosed by a cup-shaped housing equipped with a crank and a pressure plate. Together with a rim the housing forms the actual lid which closes off the container receiving the chopped food. Pressure is exerted on the ice cubes by the pressure plate resting on the ice cubes. The fact that the pressure plate is non-rotatably but axially slidably connected with the rotary cylinder means that said cylinder is set in rotation when the crank is turned. A blade is arranged in radial direction on the bottom of the lid, quasi like a plane. When the device is operated the ice cubes are xe2x80x9cshavedxe2x80x9d into fine slivers by the rotary movement and the pressure exerted by the pressure plate. The ice slivers then drop into the lower lying collecting zone of the container.
With this device the rotary movement has to be accompanied by vertical pressure applied from above via the pressure plate onto the ice cubes, which requires an accordingly elaborate bearing arrangement. Furthermore, the size of the ice slivers is determined by the plane gap and can be varied to only a very small extent. The chopped pieces of ice are comprised preferably of sliver-shaped, thin sections of a pulp-like nature. A relatively great effort is required to cut ice. Furthermore, ice is generally difficult to cut because it can easily slip off the cutter during the slightest rotary movements.
It is an object of the present invention to eliminate the disadvantages of the prior art described and to provide an improved solution of a device for chopping food, particularly pieces of ice, raw firm vegetables, dried fruit etc., which may also be used as an energy-consuming attachment on existing kitchen appliances driven by an electric motor to chop food, particularly pieces of ice, in simple manner so that said pieces of ice do not exceed a certain size nor are too small.
This object is accomplished by a device with the features of patent claim 1. Advantageous embodiments of the invention are described in the sub-claims. The advantage of the device according to the invention is, on the one hand, that food materials such as ice cubes, nuts, vegetable salads etc. have to be reduced once they attain a certain size. This saves energy and results in a relatively uniform size of reduced food particles. On the other hand this means that in addition to dried fruit and raw but firm vegetables it is also possible to reduce ice cubes without the chopping tool absorbing energy in major amounts and without the reduced parts beginning to melt. The embodiment of the invention with the features of patent claim 1 may provide, for example, a stainless steel sieve, a plastic sieve or a wire sieve. It is possible for said sieve to be cylindrical, conical or hemispherical, for example. The size of the food particles which, after being chopped, may enter the collecting zone from the processing zone may be determined by suitable selection of the sieve openings.
In this embodiment the processing zone and the collecting zone are preferably arranged vertically one above the other in the container body which, for example, may take the shape of a cylinder, the frustum of a cone or some other hollow form. By arranging the processing zone above the collecting zone, the chopped food materials may ultimately drop from top to bottom by force of gravity, enabling the unprocessed food in the processing zone to be moved from top to bottom towards the bite of the processing tool. According to the invention the movement needed to chop the food is ensured by the rotating processing tool which by virtue of its high speed of rotation not only chops or disintegrates and/or shreds the food but also forces or centrifuges the food materials out through the openings when they have become small enough. As a result of the bearing pin arrangement on the sieve bottom the tool spindle bearing arrangement is restricted to only the chopping device. The bearing arrangement takes the form, for example, of a sliding bearing, i.e., mounted on the tool spindle is a soft metal bushing made of brass, for example, into which a bearing pin projects. In this arrangement the bearing pin is fastened to the bottom of the sieve, for example. The sieve bottom acts simultaneously as the running surface for the soft metal bearing bushing. This arrangement affords simplicity and economy of manufacture.
It is particularly advantageous for the sieve to be constructed with the features of patent claim 2. This construction enables the food to be fed either through the openings in the bottom, through the openings in the side wall or through both sieve zones provided that openings are constructed there. With lateral openings (claim 3) and the relatively high speed of the processing tool, the chopped food materials are centrifuged at a high centrifugal force against the openings and forced out through the openings. High speeds may be reached in particular with devices driven by an electric motor. Only such food remains therefore in the processing zone as has not yet attained the size of the openings in the sieve.
A particular advantage is the speedy processing of the food accomplished by an embodiment in which the chopping tool has its full circumference surrounded by a downwardly tapering sieve wall. The sieve wall may also be constructed as a truncated cone.
The features of patent claim 4 disclose a further advantageous embodiment of the present invention. The chopping device may thus be put to various uses to accommodate different types of food and different degrees of chopping. For example, it is possible to produce coarsely chopped vegetable salads and fine fruit purees. Throughput can be varied by means of counter-rotating sieves having registering transverse slits which are opened to a greater or lesser degree by turning.
The features of patent claim 5 disclose a further advantageous aspect of the present invention. Such a construction is particularly hygienic because it also enables the sieve holder to be removed from the container body for cleaning. By providing for different sieve holders it is also easy to adapt the present invention to different kitchen appliances and different chopping tools. The sieve holder may be made either of metal or of plastic. At its lower end it has an inwardly projecting rim or collar in which a circumferential holding rim of the sieve or projecting holding lugs of the sieve are held.
A further advantageous embodiment of the present invention provides for a construction with the features of patent claim 6. In this construction the vertical ribs extending parallel to the center axis of the container cooperate with corresponding cutouts in the wall of the sieve holder. Here the ribs perform a dual function. On the one hand they serve as a guide for the sieve holder, on the other hand they provide the sieve holder with an upper stop hence serving as a vertical positioning device for the sieve holder. The sieve holder is thus fixed, i.e., carried in its vertical position, and simultaneously secured against being turned as, for example, by the particles of food rotating as a result of the rotary movement of the chopping tool.
In this arrangement the chopping tool is advantageously constructed in accordance with the features of patent claim 7. It is also possible, however, to use a different suitable construction other than blades. In particular in cases where four blades are used, rotation without imbalance and highly effective chopping of food results.
The blades are of different construction in accordance with the features of patent claim 8, for example. This prevents skimming of the chopping tool over the bed of food particles needing to be displaced as it rotates in hydroplane fashion.
It is particularly advantageous for the present invention to be constructed with the features of patent claim 9 because then there is no need for the device to have its own drive unit but instead may use the drive unit of a kitchen appliance which is required in any case in the household.
Finally, it is an advantage for the sieve to be interchangeable, thus enabling the use of coarser, finer or adjustable sieves (claim 10).